[PATCH] Fix ICE with bogus posix_memalign call (PR middle-end/67222)

[Marek Polacek]

Here we were crashing on an invalid call to posix_memalign.  The code in
lower_builtin_posix_memalign assumed that the call had valid arguments.
The reason the C FE doesn't reject this code is, in short, that
int <T> () is compatible with int <T> (void **, size_t, size_t) and we
use the former -- so convert_arguments doesn't complain.

So I think let's validate the arguments in lower_stmt.  I decided to
give an error if we see an invalid usage of posix_memalign, since
other code (e.g. alias machinery) assumes correct arguments as well.

Bootstrapped/regtested on x86_64-linux, ok for trunk?

2015-08-17  Marek Polacek  <pola...@redhat.com>

        PR middle-end/67222
        * gimple-low.c: Include "builtins.h".
        (lower_stmt): Validate arguments of posix_memalign.

        * gcc.dg/torture/pr67222.c: New test.

diff --git gcc/gimple-low.c gcc/gimple-low.c
index d4697e2..03194f0 100644
--- gcc/gimple-low.c
+++ gcc/gimple-low.c
@@ -39,6 +39,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "langhooks.h"
 #include "gimple-low.h"
 #include "tree-nested.h"
+#include "builtins.h"
 
 /* The differences between High GIMPLE and Low GIMPLE are the
    following:
@@ -345,10 +346,22 @@ lower_stmt (gimple_stmt_iterator *gsi, struct lower_data 
*data)
                data->cannot_fallthru = false;
                return;
              }
-           else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_POSIX_MEMALIGN
-                    && flag_tree_bit_ccp)
+           else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_POSIX_MEMALIGN)
              {
-               lower_builtin_posix_memalign (gsi);
+               if (gimple_call_num_args (stmt) != 3
+                   || !validate_gimple_arglist (dyn_cast <gcall *> (stmt),
+                                                POINTER_TYPE, INTEGER_TYPE,
+                                                INTEGER_TYPE, VOID_TYPE))
+                 {
+                   error_at (gimple_location (stmt), "invalid arguments "
+                             "to %qD", decl);
+                   gsi_next (gsi);
+                   return;
+                 }
+               if (flag_tree_bit_ccp)
+                 lower_builtin_posix_memalign (gsi);
+               else
+                 gsi_next (gsi);
                return;
              }
          }
diff --git gcc/testsuite/gcc.dg/torture/pr67222.c 
gcc/testsuite/gcc.dg/torture/pr67222.c
index e69de29..cf39aa1 100644
--- gcc/testsuite/gcc.dg/torture/pr67222.c
+++ gcc/testsuite/gcc.dg/torture/pr67222.c
@@ -0,0 +1,19 @@
+/* { dg-do compile } */
+/* { dg-options "-Wno-implicit-function-declaration" } */
+
+void
+foo (void **p)
+{
+  posix_memalign (); /* { dg-error "invalid arguments" } */
+  posix_memalign (p); /* { dg-error "invalid arguments" } */
+  posix_memalign (0); /* { dg-error "invalid arguments" } */
+  posix_memalign (p, 1); /* { dg-error "invalid arguments" } */
+  posix_memalign (p, "foo"); /* { dg-error "invalid arguments" } */
+  posix_memalign ("gnu", "gcc"); /* { dg-error "invalid arguments" } */
+  posix_memalign (1, p); /* { dg-error "invalid arguments" } */
+  posix_memalign (1, 2); /* { dg-error "invalid arguments" } */
+  posix_memalign (1, 2, 3); /* { dg-error "invalid arguments" } */
+  posix_memalign (p, p, p); /* { dg-error "invalid arguments" } */
+  posix_memalign (p, "qui", 3); /* { dg-error "invalid arguments" } */
+  posix_memalign (p, 1, 2);
+}

        Marek